问题
单项选择题 A1型题
不属于病例对照研究特点的是（）
A.属于观察性研究
B.设立对照组
C.可计算发病率
D.观察方向是“因”到“果”
E.难以验证因果关系
答案
参考答案：C
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不属于病例对照研究特点的是（）
A.属于观察性研究
B.设立对照组
C.可计算发病率
D.观察方向是“因”到“果”
E.难以验证因果关系
参考答案：C
| 完形填空。 | |||
| Doctors tell us holidays are important. We should have a rest from __1__ for a week or two every year. If it is possible, they say, we should __2__ our homes and go to another __3__ of the country. We should go away for__4__. Then after the holidays, we will be __5__ and get ready for __6__ again. But some people didn't want to __7__ their homes to stay in other places. They don't like a sudden change in their lives. They like their homes __8__ of all. And some people can have a rest in __9__ way. They can move to visit friends and get their holidays __10__ together. | |||
| ( ) 1. A. study ( ) 2. A. leave ( ) 3. A. company ( ) 4. A. sports ( ) 5. A. happy ( ) 7. A. come ( ) 8. A. good ( ) 9. A. one ( ) 10. A. well | B. duty B. stay B. school B. holidays B. excited B. go B. best B. other B. better | C. school C. come C. part C. study C. healthy C. stay C. well C. others C. best | D. work D. go D. club D. work D. good D. leave D. better D. another D. good |